math
kara needs 35 for an aquarium for 6 fish. how can she pay with the least ten and one dollar bills?October 11, 2012

physics
A 16-kg sled is being pulled along the horizontal snow-covered ground by a horizontal force of 35 N. Starting from rest, the sled attains a speed of 2.1 m/s in 9.5 m. Find the coefficient of kinetic friction between the runners of the sled and the snow.October 4, 2012

physics
A person pulls a toboggan for a distance of 34.6 m along the snow with a rope directed 29.3 ° above the snow. The tension in the rope is 110 N. (a) How much work is done on the toboggan by the tension force? (b) How much work is done if the same tension is directed ...October 4, 2012

physics
A lighthouse that rises 46.0 ft above the surface of the water sits on a rocky cliff that extends 19 ft out into the ocean from the base of the lighthouse. A sailor on the forward deck of a ship sights the top of the lighthouse at an angle of 25.0 degrees above the horizontal...September 9, 2012

Physics
container factory uses a 450 W motor to operate a conveyor belt that lifts containers from one floor to another. To lift 250 1-kg containers a vertical distance of 2.4 m, the motor runs for 45 s. What is the efficiency of the motorized conveyor system?July 18, 2012

Science
A car's engine is only 12% efficient at converting chemical energy in gasoline into mechanical energy. If it takes 1.8 x 104 N of force to keep the car moving at a constant speed of 21 m/s, how much chemical energy would be needed to move the car a distance of 450 m at ...July 18, 2012

Physics
A student applies a force of magnitude 39.0 N at an angle of 22.6o with the horizontal to push a 4.00-kg textbook 1.00 m across a table from rest to a final speed of 1.75 m/s. Find the work done by friction on the textbook.July 18, 2012

Physics
container factory uses a 450 W motor to operate a conveyor belt that lifts containers from one floor to another. To lift 250 1-kg containers a vertical distance of 2.4 m, the motor runs for 45 s. What is the efficiency of the motorized conveyor system?July 18, 2012

Physics
In this problem, your task is to analyze a lead balloon. The balloon in question is a hollow sphere of diameter of 20.0 m, constructed from a lead foil 0.25 mm thick and filled with helium gas. Below the balloon, a passenger basket is suspended. The mass of the passenger ...June 15, 2012

math
in one elementary school class the following information on sports preferences was obtained: 7 liked tennis; 11 liked baseball; 9 liked soccer; 5 liked tennis and baseball; 3 liked baseball and soccer; 2 liked tennis and soccer; and 2 liked all three sports. How many students ...June 13, 2012

econimics
Suppose that two people, Michelle and James each live alone in an isolated region. They each have the same resources available, and they grow potatoes and raise chickens. If Michelle devotes all her resources to growing potatoes, she can raise 200 pounds of potatoes per year. ...June 9, 2012

math
whats th eanswer to the math page. why do elephants have ivory tusks? and the answer to what can you use to tie up a spaceship?June 6, 2012

geometry
william wishes to carpet his rectangular5 patio, whose dimensions are 21 feet by 18 feet. How much will it cost William to cover his patio if the carpet costs $4.95 per square yard?May 3, 2012

math
Lois wants to send a box of oranges to a friend by mail. The box of oranges cannot exceed a mass of 10 kg. If each orange has a mass of 200g, what is the maximum number she can send?April 18, 2012

math
last week bre ran 28 miles more than heather. bre ran 35 miles. how many miles did heather run?March 25, 2012

math
last week Ann ran 27 miles less than Jen. Ann ran 19 miles. How many miles did Jen run?March 25, 2012

geometry
The perimeterof a square is 32 inches. Find the lenght of its diagonal. the answers should be in simplest form. make a sketch and show work.March 21, 2012

geometry
a ladder is 15 ft long and is leaning against the wall. the top of the ladder is 12 feet above the ground. find the distance from the bottom of the ladder to the wall. draw and label a picture and show work....March 20, 2012

math
What is the value of the output for the function, g(c) = 19 c2, if the input is 4?March 1, 2012

Physics
A mass of 2.2kg is placed on a stiff vertical spring which has a spring constant of 950n/m. The object is then pressed against the spring until it has been compressed a distance of 77cm. The mass is then released and is allowed to be thrown up into the air. How high in the ...February 25, 2012

Physics
A spring is mounted horizontally. A crate which has a mass of 8.5kg is pressed against the spring with a force of 350N. As a result the spring is compressed a distance of 82.0cm. The mass is then released and is allowed to slide along the horizontal, frictionless surface. What...February 25, 2012

Physics
A box which has a mass of 14kg is sliding along a horizontal surface with a velocity of 18m/s when it encounters a frictionless inclined plane which meets the horizontal at an angle of 28 degrees. The box slides up the incline until it comes to a halt. How far up the incline ...February 25, 2012

Physics
A 25kg crate is sitting at the bottom of an inclined plane. The inclined plane 12m long meets the horizontal at an angle of 15 degrees and has a coefficient of friction of 0.55. A force is applied to the crate so as to slide the crate up the incline at a constant speed. What ...February 25, 2012

College Geology
assume that a particular radioactive-isotope has a half-life of 100 million years. Also assume that the parent isotope is incorporated into the minerals found in igneous rocks and that the only daughter atoms in the rock formed from the decay of the parent isotope. ...February 22, 2012

Chemistry
If you are using 5.25% (mass/mass) bleach solution and you determine that the density of the bleach solution is 1.08 g/mL, how many moles of sodium hypochlorite are present in a 4.00 mL sample?January 31, 2012

Chemistry
If you are using 5.25% (mass/mass) bleach solution and you determine that the density of the bleach solution is 1.08 g/mL, how many moles of sodium hypochlorite are present in a 4.00 mL sample?January 31, 2012

college algebra
11. Students in an accounting class took a final exam and then took equivalent forms of the exam at monthly intervals thereafter. The average score as a percent, after t months was given byJanuary 31, 2012

APUSH
The above answer in incorrect. Eventhough there was monopolies which were created by the govt. through loans, as all monopolies are created, thiis time period was an excellent one for the u.s.a Trists developed through innovation using the bessemer proccess and vertical and ...January 24, 2012

Essay
I need to do an essay but need to know if it is usually blank percent rainy or blank persent sunny usually in Port Saint Lucie? Can you help or give me a website that gives me percentages on how it usually is.January 3, 2012

calculus
prove that 5x - 7 - sin3x = 0 has at least one zero and prove that it has exactly one real zero. How am I supposed to show my work for this? I don't really understand how to show my work for the IVT. Without that I can't do any work for the MVT.December 16, 2011

physics
One gram of water changes from liquid to solid at a constant pressure of one atmosphere and a constant temperature of 0°C. In the process, the volume changes from 0.90 cm3 to 1.10 cm3. The work done by the water is .02J, but I'm not sure how to find the internal energy...November 17, 2011

Math
Random variables X and Y are both normally distributed with mean 100 and standard deviation 4. It is known that random variable X+Y is also a normal distribution. a. What is the mean of X+Y? b. What is the standard deviation of X+Y? I see that the mean is 200 but I don't ...November 15, 2011

Science
If earths mass were reduced by 1/2 , but its radious satyed the same , how much would your weight change ? Would it also be reduced by half ?October 17, 2011

general chem
Calculate the molarity of a solution made by dissolving 12.5 grams of Na2CrO4 in enough water to form exactly 550 mL of solution. (b) How many moles of KBr are present in 150 mL of a 0.275 M solution? (c) How many milliters of 6.1 M HCl solution are needed to obtain 0.100 mol ...October 9, 2011

general chem
Calculate the molarity of a solution made by dissolving 12.5 grams of Na2CrO4 in enough water to form exactly 550 mL of solution. (b) How many moles of KBr are present in 150 mL of a 0.275 M solution? (c) How many milliters of 6.1 M HCl solution are needed to obtain 0.100 mol ...October 9, 2011

general chem
Using the activity series (Table 4.5), write balanced chemical equations for the following reactions. If no reaction occurs, simply write NR. (a) Nickel metal is added to a solution of copper (II) nitrate; (b) a solution of zinc nitrate is added to a solution of magnesium ...October 9, 2011

general chem
Determine the oxidation number for the indicated element in each of the following compounds: (a) Co in LiCoO2, (b) Al in NaAlH4, (c) C in CH3OH (methanol), (d) N in GaN, (e) Cl in HClO2, (f) Cr in BaCrO4.October 9, 2011

physics
A ball launched from ground level lands 3 s later on a level field 48 m away from the launch point. Find the magnitude of the initial velocity vector and the angle it is above the horizontal. (Ignore any effects due to air resistance.)September 28, 2011

math
find the eqt. of tangent to the curve y=-x^2+2x-10 @ the point where the curve cuts the y-axis.[ans:y=2x-10] how do i do this because they didn't give me the point...?July 22, 2011

math
the tangent yo the curve y=x^2 +5x -2 @ the point (1,4)intersect the normal to the same curve @ the point (-3,-8) at the point P.Find the coordinates of point P.[ans: -1/3,-16/3] just give me some hint to calculate this solution.July 22, 2011

math
in the question it say: at the point where the curve cuts the y-axisJuly 22, 2011

physics
if i crate is been dragged with 500 n of force with a 15 degree angle what would the horizontal force be?May 29, 2011

algebra
Tina Mixes pretzels that sell for $2 a lb with cereal that sells for $3 a lb. she wants to make an 8 lb mixture to sell for $2.50. write 2 equations to represent this info. How many lbs of pretzels and how many lbs of cereal were used to make the 8 lb mixture?May 24, 2011

English
In the Kite Runner, why is the story about the sultans included? What is that story about?May 1, 2011

Physics
Tom Brady passes a football  at a velocity of 50 ft/s at an angle of 40 degrees to the horizontal  toward an intended receiver 30 yd straight downfield. The pass is released 5 ft above the ground. Assume that the receiver is stationary, is isolated and that he can ...April 25, 2011

Physics
You have a tiny slip of paper and a large rectangular wooden block. If you put both of them side-by-side and drop the two to the floor from the same height, the block gets to the floor first. Can you think of (and describe) three simple ways (using nothing, ...April 25, 2011

Physics
You are driving your race car around a circular test track. Which would have a greater effect on the magnitude of your acceleration, doubling your speed or moving to a track with half the radius? Why?April 25, 2011

Physics
An object is executing circular orbits of radius 0.5 m. If it completes an orbit every 3 seconds, what is its tangential speed?April 25, 2011

Physics
f a water bed is 1.81 m on each vertical side and 30 cm high. Find its weight. The acceleration of gravity is 9.8 m/s2 and the density of water is 1000 kg/m3. Answer in units of NApril 15, 2011

physics
An acorn and tree leaf fall from the same height and time. Which reaches the ground first and why?April 9, 2011

pharmacy tech
Determine the milliliters of water needed to prepare 2 oz of a 10% solution from a 12.5% solution and distilled water.April 4, 2011

pharmacy tech
Determine the milliliters of water needed to prepare 2 oz of a 10% solution from a 12.5% solution and distilled water.April 4, 2011

Physics- 2D Collisions
nitially, mass one (2.10 kg) has a velocity of 5.90 m/s and mass two (2.80 kg) is at rest. After they collide, mass one emerges at an angle theta = 33.0 degrees. What is the speed of mass one after the collision if the collision is completely elastic? (Note, there are actually...March 29, 2011

Physics
A tennis ball of mass 0.0609 kg is served. It strikes the ground with a velocity of 52.5 m/s (117 mi/h) at an angle of 22.0° below the horizontal. Just after the bounce it is moving at 50.5 m/s at an angle of 17.7° above the horizontal. If the interaction with the ...March 28, 2011

Stats.
An obstetrician maintains that preterm babies (gestation less than 37 weeks) have a higher variability of birth weight than do full-term babies (gestation 37-41 weeks). According to the National Vital Statistics Report, Vol. 48, No. 3, the birth weights of full time babies ...March 28, 2011

Physics
A tennis ball of mass 0.0609 kg is served. It strikes the ground with a velocity of 52.5 m/s (117 mi/h) at an angle of 22.0° below the horizontal. Just after the bounce it is moving at 50.5 m/s at an angle of 17.7° above the horizontal. If the interaction with the ...March 27, 2011

Math
a plane flies due north at 300 mi/h for 3 h then due west at 250 mi/h. If x represents the number of hours the plane is flying due west, determine for what values of x the plane will be more than 3700 mi from it's original point.March 8, 2011

statistics
An obstetrician maintains that preterm babies (gestation less than 37 weeks) have a higher variability of birth weight than do full-term babies (gestation 37-41 weeks). According to the National Vital Statistics Report, Vol. 48, No. 3, the birth weights of full time babies are...March 7, 2011

statistics
Part 1) A physical therapists wishes to determine whether an exercise program increases flexibility. He measures the flexibility (in inches) of 12 randomly selected subjects both before and after an intensive eight-week training program and obtains the following data: Before: ...March 7, 2011

Statistics
Part 1) Exposure to dust at work can lead to lung disease later in life. In a study of 115 drill and blast workers involved in tunnel construction the mean dust exposure was 18.0 mg-yr/m^3 with a standard deviation of 7.8 mg-yr/m^3 (sample 1). Another study of 220 outdoor ...March 7, 2011